Cultivation experience of Sweet Potato in protected Field

The precocious cultivation of sweet potato in large and medium greenhouse facilities can not only improve the utilization rate of limited land resources, light and heat resources, improve the yield and benefit of sweet potato production, but also realize the double-season cultivation of sweet potato in the suburbs of Beijing. promote the reform of planting system.

I. site selection and construction of sheds

In the cultivation of sweet potato in protected land, the stubble land with a rotation period of more than three years should be selected, and the sandy loam is the ideal soil. Sweet potato fields which have been cropped for more than two years are easy to cause the prevalence of soil-borne diseases such as sweet potato nematode disease and black spot disease and the imbalance of soil nutrient elements, so soil disinfection and balanced fertilization should be adopted to increase the amount of organic fertilizer. The previous crops of the land are wheat, corn, melons and vegetables, and there should be good drainage and irrigation conditions. The construction specification and direction of the shed should be determined according to the topography and topography, and the downwind direction is generally better, which can not only reduce the influence of wind damage, but also improve the operation efficiency. The greenhouse can be built in accordance with the standard specifications of melons and vegetables, with a general span of four meters and a height of 1.2-1.5 meters. In the length of 1-1.2 meters to support a bamboo keel, the plastic film close to the keel and tight, both sides pressed into the ground about 15 cm. Buried and solid, the keel is tightened with wire or nylon rope, and whether the grass curtain is covered on the film or not depends on the local climate and planting period sooner or later. The greenhouse was built and covered with film before sweet potato planting, and the middle greenhouse was covered with film after sweet potato planting.

II. Variety selection and soil preparation

In order to give full play to the utilization effect of light and temperature resources in protected areas, early-maturing and high-yield varieties such as Yushu 10 (also known as Hongxinwang) and Jingshu 2 should be selected. Soil preparation is generally carried out in front of the plastic film, combined with the application of bottom fertilizer for leveling and deep turning. On the basis of applying 2000 kg of high-quality organic fertilizer per mu, 40-50 kg of special fertilizer for sweet potato was applied (10:7:8). After spreading, turn into the ground, need to disinfect, insecticidal plots, disinfectant and insecticidal bait are applied together. The flatness of the land in the same shed is to ensure smooth watering, drainage and ridging to cover the film. The distance between ridges is 75 cm, the ridge height is 25 cm, the top is flat, and the width is 20-25 cm. Cover the ridge with plastic film to cover the whole ridge tightly and tighten it.

3. Planting

The main results are as follows: 1. The planting time of seedlings is determined according to the harvest time and seedling raising situation. It is generally considered that it is suitable for the first and middle ten days of April of sweet potato in greenhouse and mid-late April in middle greenhouse. 2. The seedlings taken from the seedling bed can be directly planted or pseudo-planted first. According to the mild seedling classification in the production field, the seedlings were first transplanted to a warm leeward and sunny border, properly watered, and covered with plastic film in the morning and evening. Carry on the adaptive exercise and Cui Gen, generally 3-7 days can reach the suitable planting standard. The seedlings after pseudo-planting can not only improve the survival rate, but also slow down the seedlings quickly. 3. Oblique planting method or direct planting method is generally used to ensure the density of sweet potato in the protected field. The planting density per mu is determined according to the characteristics of the varieties and the planned harvest time, which is generally about 10% higher than that in ordinary fields. The seedlings were planted in the middle of the top of the ridge. after breaking the film, they were planted in the soil 4-5 cm. After watering twice, the soil was sealed and the stubble of the plastic film was broken.

IV. Management and harvest

The management of sweet potato in protected area is relatively simple, and the key is to keep heat and moisture in the early stage and slow down the seedlings. In order to promote the early and slow seedling of sweet potato, the temperature in the greenhouse is not higher than 35 degrees Celsius 3-5 days after planting, and there is generally no ventilation to maintain the internal humidity. Below 13 degrees Celsius should be airtight or artificially heated, and crosswind ventilation should be carried out above 35 degrees Celsius to prevent the cold wind from coming in. Combined with the release of wind in the ditch to loosen the soil and increase the temperature and preserve the soil moisture. After the late frost and late spring cold have completely passed, as the external temperature rises, the vent is gradually enlarged, and the sides of the ridge are all open, and the greenhouse film can be removed when the temperature reaches about 30 degrees Celsius. According to the seedling growth and soil fertility of sweet potato, before closing the ridge, opening holes on the ridge side, applying 30-40 kg special compound fertilizer per mu, and watering according to soil moisture. Promote fertilizer dissolution and prevent drought. Under the condition of protected land, 65-70 days after planting, precocious varieties can be harvested, packed and listed on the market according to market information. And pay close attention to soil preparation and soil treatment for second-crop planting. The main technical points of planting sweet potato in summer are commonly known as wheat stubble potato in the suburbs of Beijing, which mainly refers to the sweet potato planted in early spring after harvest, which is mainly different from spring sweet potato in seedling form. Spring sweet potato is collected from seed potato. Due to the differences in the conditions of light and heat resources and the growth of summer crops, the seedling stage of late-planted spring potato and early-planted summer potato is sometimes very close.

Sweet potato is native to the tropical regions of South America, and its production mainly depends on vegetative reproduction. The growth period of summer sowing sweet potato is short, and there is a great difference in growth and development between summer sowing sweet potato and spring sweet potato, but the economic benefit is very obvious. According to the investigation, the per unit yield of summer potato in the suburbs of Beijing can reach 2000kg, and the output value is more than 400 million yuan, so the scale of planting summer sweet potato in the adjustment of agricultural structure is constantly expanding.